A sailor turned up for a book of maps (5)
I believe the answer is:
atlas
'book of maps' is the definition.
(synonyms)
'a sailor turned up for a' is the wordplay.
'a sailor' becomes 'salt' (salt is a kind of sailor).
'turned up' says the letters should be written backwards.
'for' says to put letters next to each other (I've seen this in other clues).
'salt' back-to-front is 'tlas'.
'tlas' put after 'a' is 'ATLAS'.
(Other definitions for atlas that I've seen before include "African mountain range" , "Its architectural name is telamon" , "I carry a huge weight" , "Mythological Titan (involved with the world of maps?)" , "Size of paper once" .)